DE 10 2010 022 689 A1 relates to a rewiring element for an energy storage module, to a method for producing said rewiring element, and also to an energy storage module. The energy storage module comprises a plurality of storage cells which are arranged one above the other in at least one vertical row. Said storage cells are electrically interconnected to one another in pairs by means of cell connections. The rewiring element comprises a conductor track structure having a plurality of conductor tracks which are arranged next to one another and which extend in the vertical direction, and also a plurality of voltage taps of which the first ends, which face the conductor tracks, are each connected to an associated first end of a respective conductor track. The free second ends of the voltage taps are provided for cohesive connection to associated cell connectors. The voltage taps for compensating for a relative movement of the rewiring element in relation to the cell connectors and/or different extents of the rewiring element and of the cell connectors are designed as movement compensation elements.
Battery cells are typically connected to one another by means of individual lugs which are produced from copper (Cu) or aluminum (Al). In this case, electrical contact is made with terminals of adjacent battery cells by means of connecting lugs, wherein the ends of the connecting lugs are either screwed to the cell terminal or are connected to said cell terminal in a cohesive manner, for example welded to one another. Each battery generally has an associated monitoring circuit (CSC, Cell Supervision Circuit). The cell temperatures and the cell voltages are detected and forwarded to a battery control unit by means of a monitoring circuit of this kind.
The battery cell monitoring circuit is generally located on the battery housing or on the top face of said battery housing. Further embodiments in which the cell monitoring unit, like the cell monitoring circuit, is accommodated in a separate housing, which is connected to the battery module or to another part of a battery pack by means of bolts, are available.
The measuring lines for detecting the cell voltage and the cell temperature, which measuring lines extend between the cell monitoring circuit and the connections, are generally realized by embodiments:
In one embodiment, it is possible to form the signal lines as wires which are, for example, welded to the battery cell connections. Furthermore, in another embodiment, it is possible to use a flexible film, wherein the contact-making point of the flexible film is welded to the cell terminal or is welded to another connection. Furthermore, in yet another embodiment, it is possible to use a punched grid which is welded directly to a battery cell connection.
Embodiments of signal lines outlined above are associated with additional components, for example wires, a flexible film or a punched grid, being required, the use of said additional components necessarily being associated with additional costs. Furthermore, the cohesive joining process constitutes a cost factor. In general, the signal lines are used to detect the battery cell voltage and the battery cell temperature during the assembly process, and therefore there is a risk of said signal lines being damaged in subsequent assembly steps. If the cell monitoring circuit is accommodated in a separate housing, this separate housing, which is connected to the battery cell housing by means of a joining process for example, is included and therefore constitutes additional expenditure. Furthermore, accommodating the cell monitoring circuit on the cover of the battery cell is hazardous. Degassing of the battery cell may occur for example.
All in all, the previous solutions for connecting or accommodating a cell monitoring circuit (CSC, Cell Supervision Circuit) which monitors specific battery cells constitute unsatisfactory solutions, and therefore a corrective measure is offered.